### Unsteady Mixed Convection Flow of a Micropolar Fluid About a Sphere

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#### Abstract

An analysis is presented to investigate the unsteady flow and heat transfer characteristics of mixed convection flow of an electrically conducting micropolar fluid about a sphere. The transformed governing equations of the nonsimilar boundary layers are solved using the finite difference method. We also utilize the series solution method for short time and the asymptotic method for long time. A comparison is made between the numerical and the series solutions, which provides a good agreement. Numerical solutions have been carried out for a wide range of the mixed convection parameter, the vortex viscosity parameter, the spin-gradient viscosity parameter, the heat generation or absorption parameter, the conduction-radiation parameter and the magnetic field parameter. The effects of these parameters are discussed in terms of the variations of the local friction factor, couple stress and Nusselt number. Also we compare the present solutions with the existing results and found to be an excellent agreement. *Copyright © 2015 Praise Worthy Prize - All rights reserved.*

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A. C. Eringen, Theory of micropolar fluids, J. Math. Mech., 16, pp. 1–18 (1966).

http://dx.doi.org/10.1512/iumj.1967.16.16001

A. C. Eringen, Theory of thermomicropolar fluids, J. Math. Anal. Appl., 38, pp. 480–496 (1972).

T. Ariman, M. A. Turk, N. D. Sylvester, Microcontinum fluid mechanics-a review. Int. J. Eng. Sci., 11, pp. 905–930 (1973).

http://dx.doi.org/10.1016/0020-7225(73)90038-4

T. Ariman, M. A. Turk, N. D. Sylvester, Application of microcontinum fluid mechanics, Int. J. Eng. Sci., 12, pp. 273–293 (1974).

http://dx.doi.org/10.1016/0020-7225(74)90059-7

A. J. Willson, Boundary-layer in micropolar liquids, Proc. Camb. Phil. Soc., 67(2), pp. 469–476 (1970).

http://dx.doi.org/10.1017/s0305004100045746

J. Peddieson, R. P. McNitt, Boundary layer theory for a micropolar fluid, Recent Adv. Eng. Sci., 5, 405–476 (1970).

R. S. R. Gorla, Micropolar boundary layer flow at a stagnation point on a moving wall. Int. J. Eng. Sci., 21(1), pp. 25–33 (1983).

http://dx.doi.org/10.1016/0020-7225(83)90036-8

R. S. R. Gorla, The axisymmetric micropolar boundary layer on a long thin cylinder. Int. J. Eng. Sci., 22, pp. 293–299 (1984).

http://dx.doi.org/10.1016/0020-7225(84)90010-7

R. S. R. Gorla, Axisymmetric thermal boundary layer of a micropolar fluid on a cylinder. Int. J. Eng. Sci., 23, pp. 401–407 (1985).

http://dx.doi.org/10.1016/0020-7225(85)90087-4

C. A. Hieber, B. Gebhart, Mixed convection from a sphere at small Reynolds and Grashof numbers, J. Fluid Mech., 38(1), pp. 137–159 (1969).

http://dx.doi.org/10.1017/s0022112069000097

T. S. Chen, A. Mucoglu, Analysis of mixed forced and free convection about a sphere, Int. J. Heat Mass Transf., 20, pp. 867–875 (1977).

http://dx.doi.org/10.1016/0017-9310(77)90116-8

A. Mucoglu, T. S. Chen, Mixed convection about a sphere with uniform surface heat flux, J. Heat Transfer, 100(3), 542–544 (1978).

http://dx.doi.org/10.1115/1.3450846

F.-S. Lien, C.-C. Chen, Analysis of forced convection micropolar boundary layer about a permeable sphere, Int. J. Eng. Sci., 24, pp. 991–999 (1986).

http://dx.doi.org/10.1016/0020-7225(86)90031-5

F.-S. Lien, C.-C. Chen, Mixed convection of micropolar fluid about a sphere with blowing and suction, Int. J. Eng. Sci., 25, pp. 775–784 (1987).

http://dx.doi.org/10.1016/0020-7225(87)90115-7

R. Nazar, N. Amin, I. Pop, Mixed convection boundary layer flow about an isothermal sphere in a micropolar fluid, Int. J. Therm. Sci., 42, pp. 283–293 (2003).

http://dx.doi.org/10.1016/s1290-0729(02)00027-3

R. Nazar, N. Amin, I. Pop, On the mixed convection boundary layer flow about an isothermal sphere, Arabian J. Sci. Eng., 27, pp. 117–135 (2002).

http://dx.doi.org/10.1016/s1290-0729(02)00027-3

A. J. Chamkha, M. Mujtaba, A. Quadri, C. Issa, Thermal radiation effects on MHD forced convection flow adjacent to a non-isothermal wedge in the presence of heat source or sink, Heat Mass Transf., 39, pp. 305–312 (2003).

Z. Uddin, M. Kumar, S. Harmand, Influence of thermal radiation and heat generation/absorption on MHD heat transfer flow of a micropolar fluid past a wedge considering hall and ion slip currents, Thermal Sci., 18(2), pp. 489–502 (2014).

http://dx.doi.org/10.2298/tsci110712085u

A. Ishak, R. Nazar, I. Pop, MHD boundary-layer flow of a micropolar fluid past a wedge with variable wall temperature, Acta Mech., 196, pp. 75–86 (2008).

http://dx.doi.org/10.1007/s00707-007-0499-8

A. Ishak, R. Nazar, I. Pop, MHD boundary layer flow of a micropolar fluid past a wedge with constant wall heat flux, Commun. Nonlinear Sci. Numer. Simul., 14, pp. 109–118 (2009).

http://dx.doi.org/10.1016/j.cnsns.2007.07.011

A. Raptis, Flow of a micropolar fluid past a continuously moving plate by the presence of radiation, Int. J. Heat Mass Transf., 41, pp. 2865–2866 (1998).

http://dx.doi.org/10.1016/s0017-9310(98)00006-4

M. Ganapathirao, R. Ravindran, I. Pop, Non-uniform slot suction (injection) on an unsteady mixed convection flow over a wedge with chemical reaction and heat generation or absorption, Int. J. Heat Mass Transf., 67, pp. 1054–1061 (2013).

http://dx.doi.org/10.1016/j.ijheatmasstransfer.2013.08.016

N. C. Roy, M. A. Hossain, R. S. R. Gorla, Unsteady free convection from a heated sphere in the presence of internal heat generation or absorption, Int. J. Therm. Sci. 98, pp. 237–244 (2015).

http://dx.doi.org/10.1016/j.ijthermalsci.2015.07.021

E. M. Sparrow, H. S. Yu, Local non-similarity thermal boundary layer solutions, J. Heat Transf., 93 (4), pp. 328–334 (1971).

http://dx.doi.org/10.1115/1.3449827

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